Upper gastrointestinal endoscopy (also known as upper endoscopy, upper GI endoscopy, esophago-gastro-duodenoscopy [EGD], or panendoscopy) is a procedure employed by a physician to examine the lining of the upper part of a patient's gastrointestinal tract. Upper gastrointestinal endoscopy is usually used to investigate symptoms of persistent upper abdominal pain, nausea, vomiting, difficulty in swallowing, or bleeding in the upper gastrointestinal tract.
To perform gastrointestinal endoscopy, a physician inserts a thin, flexible tube with a lens, fiber optic view transmission path and light source (an endoscope) into the patient's gastrointestinal tract through the patient's mouth. The physician may be able to observe inflammation, ulcers, or tumors of the esophagus, stomach or duodenum. In addition, certain conditions may be treated. By inserting a variety of instruments through a lumen in the endoscope, a physician may stretch narrowed areas, remove polyps, retrieve swallowed objects, or treat bleeding.
A patient prepares for an endoscopy by fasting to clear the gastrointestinal tract. The physician may spray a local anesthetic into the patient's throat before the test and intravenous or other medication may be given to help the patient relax. A bite block may be placed in the patient's mouth to keep the patient's jaws open. A prior art bite block 10 is illustrated in FIG. 1. The bite block 10 comprises a tubular body 12, having a proximal end 14 and a distal end 16. A channel 18 extends through the tubular body 12. The endoscope (not shown) or other instruments may be inserted through this channel into the patient's throat. A shield 20 at the proximal end 14 of the bite block 10 has left and right lateral wings 22, 24 respectively, which shield a part of the patient's lips and extend onto the patient's left and right cheeks. Each wing 22, 24 has a tab or clip 26, 28. An elastic band (not shown) may be attached to the clips 26, 28 and passed around the patient's head to secure the bite block. In the usual case, the endoscope or other instrument is then partially coated with a sterile, bio-compatible lubricant, for example, petroleum jelly, to aide in inserting the endoscope into the throat.
Although a upper gastrointestinal endoscopy is a widely used procedure, it is sometimes difficult to insert the endoscope. Because of the medication given to the patient to relax the patient's muscles, the patient's tongue will sometimes relax into the back of the patient's mouth, sometimes covering or entering the channel 18 of the bite block 10 and blocking the patient's throat. Moreover, manually applying lubricant to the exterior of an endoscope may present difficulties in handling and sterilizing the endoscope or the lubricant. Finally, it is sometimes desirable to insert and additional cannula or device past the bite block and into the back of the throat, while isolating the additional cannula or device (e.g., a needle, suction tube, oxygen supply line or other such device) from the endoscope. There remains a need, therefore, for additional improvements in the instrumentation used for gastrointestinal endoscopy.